کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5739717 1412115 2017 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Original ArticleCarotenoid production and phenotypic variation in Azospirillum brasilense
موضوعات مرتبط
علوم زیستی و بیوفناوری ایمنی شناسی و میکروب شناسی میکروبیولوژی و بیوتکنولوژی کاربردی
پیش نمایش صفحه اول مقاله
Original ArticleCarotenoid production and phenotypic variation in Azospirillum brasilense
چکیده انگلیسی

We assessed the occurrence of phenotypic variation in Azospirillum brasilense strains Sp7, Cd, Sp245, Az39 and phv2 during growth in rich media, screening for variants altered in colony pigmentation or extracellular polysaccharide (EPS) production. Previous studies showed that EPS-overproducing variants of Sp7 appear frequently following starvation or growth in minimal medium. In contrast, no such variants were detected during growth in rich media in the tested strains except for few variants of phv2. Regarding alteration in colony pigmentation (from pink to white in strain Cd and from white to pink in the others), strain Sp7 showed a relatively high frequency of variation (0.009-0.026%). Strain Cd showed a lower frequency of alteration in pigmentation (0-0.008%), and this type of variation was not detected in the other strains. In A. brasilense, carotenoid synthesis is controlled by two RpoE sigma factors and their cognate ChrR anti-sigma factors, the latter acting as negative regulators of carotenoid synthesis. Here, all tested (n = 28) pink variants of Sp7 carried mutations in one of the anti-sigma factor genes, chrR1. Our findings indicate that, in A. brasilense, phenotypic variation is strain- and environment-dependent and support the central role of ChrR1 in regulation of carotenoid production.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Research in Microbiology - Volume 168, Issue 5, June 2017, Pages 493-501
نویسندگان
, , , ,